In the plumbing industry, drainage traps are fixtures having a U-, J-, S-, or P-shaped portion and are used to trap fumes, gases, and odors within a drainage piping system. Most plumbing fixtures, such as bathroom sinks, kitchen sinks, bath tubs and water closets, include a drainage trap. A drainage trap may either be an integral part of the plumbing fixture or a separate fixture that can be releasably coupled to the plumbing fixture. In the present application, “internal traps” should be understood to be drainage traps that are an integral part of the plumbing fixture, and “external traps” should be understood to be drainage traps that can be releasably coupled to the plumbing fixture. It is to be appreciated that external traps are more common than internal traps, but in any embodiment described herein, external and internal traps can be substituted for each other.
Once the drainage trap is installed, water is flushed down the plumbing fixture, and the shape of the drainage trap allows a small pool of water to be retained within the drainage trap. The pool of water in the drainage trap functions as a seal that prevents the fumes, gases, and odors from escaping into the external living space in a building.